David Cameron has hired a pair of senior advisers to President Obama to help in his election campaign against Gordon Brown, I can reveal. They have been appointed to help prepare him for his TV debates with the Prime Minister.

Until November, one of the advisers – Anita Dunn – was Communications Director at the White House. The other, Bill Knapp, also worked on the Obama election campaign (making TV ads particularly). Knapp is very close to New York Mayor Mike Bloomberg, a lifelong Democrat who has run and won election in the city as a registered Republican three times.

The Tories have signed a contract with their firm – Squier, Knapp, Dunn Communications, which is a leading Washington-based Democrat-leaning political consultancy – specifically for help with TV debates. But the firm is also expected to offer advice more broadly to the Tory leader on the direction of the Conservative campaign.

Gordon Brown recently also turned to the U.S. for advice, reportedly taking on Joel Benenson, a polling and strategy adviser who worked in the team that readied Mr Obama for his set-piece TV clashes with John McCain.

The gap between the parties has narrowed of late, and there’s growing consternation in Conservative ranks. However, the Tories say they have been in talks with the U.S. firm for several months following a recommendation from Michael Bloomberg. He maintains close ties with the Tory leadership.

Ms. Dunn is a veteran of Democrat politics, beginning her career in Jimmy Carter’s administration and subsequently working as a consultant on many election campaigns. She returned to the White House with President Obama but then left late last year when her husband, Robert Bauer, the President’s personal attorney, was unveiled as the incoming White House counsel.

Bill Knapp has worked on five presidential campaigns, including the Obama bid for the White House.

It’s certainly a turn up for the Tories to hire advisers so closely associated with the Democratic party. Traditionally the party maintains links with the Republicans and Labour looks to the Democrats.

Labour is likely to be rather bemused by this development, with those in charge of the campaign presuming they had a monopoly on links with those close to Obama. It appears that was a mistaken presumption. In the current febrile atmosphere this is a fascinating move by the Tory leader.